In general, the present invention relates to apparatus and methods for receiving, processing and dispensing compensation for empty used containers. Such apparatus and methods are hereinafter sometimes referred to as "reverse vending" apparatus and methods in that a customer is compensated for return of empty containers as compared with "vending" apparatus and methods whereby a customer receives a full container upon deposit of compensation.
The apparatus and methods of the present invention are particularly adapted for use in connection with recovery of aluminum can-type beverage containers which presently have a scrap value substantially in excess of other types of commonly used containers made of steel, glass, plastic, paper and the like.
There is a substantial amount of prior art in the reverse vending field which includes: (1) batch type apparatus and methods whereby multiple empty containers may be simultaneously received and processed; and (2) single container type apparatus and methods for receiving and processing one container at a time. Myers U.S. Pat. No. Re. 27,643 and Wu, et al. U.S. Pat. No. 4,241,821 are examples of single container reverse vending apparatus and methods. Spears, et al. U.S. Pat. No. 3,749,240 and Miller U.S. Pat. No. 4,179,018 are examples of batch type apparatus and methods. The Myers patent discloses the basic concept of can collection apparatus for receiving a used can, separating cans of various materials, crushing the cans and dispensing something of monetary value, such as coins or a token, in accordance with the value of the cans received. Since then, a substantial effort has been made to further develop such can collection apparatus for the purpose of implementing a recycling system whereby used cans may be efficiently collected from the general public and returned to sheet metal manufacturers for reuse in the manufacture of sheet metal.
In general, prior art reverse vending apparatus and methods have included a housing containing container receiving means for receiving used empty containers; classification or separation means for separating particular types of containers, such as empty aluminum containers, from other types of containers such as steel or glass containers; container crushing means for crushing selected types of containers; container storage means for storing the containers; conveyor means for transporting the containers to the container crushing means and the container storage means; measuring means for determining the amount of selected types of containers received; and dispensing means for dispensing compensation proportional to the value of the selected types of containers received.
Prior art reverse vending apparatus and methods have employed a variety of combinations of specially constructed and arranged separator means, such as positive or negative air flow, magnetics and gravity, to separate aluminum from steel or glass containers. Spears, et al. U.S. Pat. No. 3,749,240 discloses apparatus for and method of classifying empty containers at a single classification station at the upper end of an upwardly inclined conveyor by use of a combination of gravity, pressurized air and magnetic apparatus and methods. Miller U.S. Pat. No. 4,179,018 also discloses a method and apparatus for selective recovery of metal containers by use of a combination of gravity, pressurized air and magnetic apparatus and methods. In Miller, aluminum cans are first separated from steel cans and other articles, then blown to a crusher device, then the crushed cans are weighed to determine the amount of compensation to be dispensed, and then the crushed cans are blown to an overhead storage area. In addition, the use of pressurized air to convey empty aluminum can bodies has been known in the aluminum can manufacturing industry since at least 1965.
One of the problems with prior art batch type reverse vending apparatus for collection of cans has been the high cost of manufacture and the lack of adequate can storage capacity without the use of a relatively large housing. In addition, such apparatus has been energy inefficient and required the use of a relatively large number of parts spread out over a relatively large area requiring a relatively large volume housing. The prior art apparatus has not provided for crushing of both aluminum and steel cans. Also, there have been operational problems with the crushing apparatus and the crushed cans have not had optimum density characteristics. Another problem has been lack of accuracy of measurement of weight of aluminum cans and dispensing of the proper amount of compensation. Such apparatus has been subject to vandalism and thievery. The speed of operation of some apparatus has been relatively slow and control systems have been inadequate and unreliable.
The present invention provides a relatively small size compact arrangement of container separation means, container conveying means, container crushing means, container weighing means, and container storage means which are operable in a more energy efficient manner than prior art apparatus.
In general, the apparatus of the present invention comprises a multiple can collection bin means for receiving and temporarily holding articles to be processed; an upwardly inclined belt conveyor means associated with an open lower portion of the collection bin means for removing articles from the bin means and carrying articles upwardly away from the collection bin means to an upwardly spaced discharge location whereat the articles are outwardly downwardly discharged as the belt conveyor means turns around an uppermost pulley device; a combination air classifier and empty can conveyor means located in juxtaposition to the belt conveyor means for receiving articles discharged from the belt conveyor means and separating lightweight empty aluminum and steel cans from heavier articles such as bottles and filled cans while upwardly conveying empty cans toward a discharge opening; a crusher means located opposite the discharge opening for receiving and crushing empty aluminum and steel cans; a magnetic separator means located directly beneath and in juxtaposition to the lower portion of the crusher means for receiving and separating crushed aluminum and steel cans; a weighing means located beneath and in juxtaposition to the magnetic separator means for receiving and weighing crushed aluminum cans; and an air blower type crushed can conveying means located in juxtaposition to the weighing means for conveying crushed aluminum cans to a storage bin.
In the presently preferred embodiment, the collection bin means and the belt conveyor means are constructed and arranged so that the conveyor means ordinarily removes groups of articles from the bin means and carries each group of articles upwardly on one of a plurality of longitudinally spaced support rib devices attached to, extending outwardly from, and being laterally inclined across a continuous loop belt member so that each article of each group of articles is ordinarily separated from the other articles of each group during discharge from the conveyor means. The air classifier and empty can conveyor means comprises a single low pressure high volume air blower means which is preferably connected to a relatively short length inclined air passage means extending parallel to the belt conveyor means. An article inlet opening is provided in an upper portion of the air passage means adjacent and below the article discharge location of the belt conveyor means to receive articles discharged from the belt conveyor means. A heavy article outlet opening is provided at the lower end of the air passage means opposite and below the article inlet opening adjacent the air blower means whereby heavy articles, such as bottles and filled cans, fall by gravity from the inlet opening to the outlet opening through the air stream in the air passage means. Empty aluminum and steel cans are blown upwardly and conveyed in the air stream in the air passage means to the crusher means.
In a presently preferred embodiment of the invention, the crusher means comprises an oscillating blade member mounted in a hopper device for pivotal movement between spaced inclined side walls of the hopper device whereby empty cans may be crushed during movement of the blade member in either direction. Anti-jamming control means are provided to automatically reverse the direction of movement of the blade member whenever a jam condition in the crusher is sensed. In addition, if a jam condition is sensed for a predetermined period of time, operation of all apparatus is automatically terminated until manual repairs are made.
In another embodiment of the invention, the crusher comprises a pair of inwardly inclined steel alloy open link endless conveyor belt members which define a tapered can crushing passage of gradually reduced cross-sectional area therebetween having a relatively wide inlet opening at one end located next adjacent the air passage and a relatively narrow outlet opening at the other end. The inlet opening is substantially larger than the uncrushed cans to enable uncrushed cans to be blown into the can passage. At an intermediate portion of the can passage, its cross-sectional area becomes less than the cross-sectional area of the uncrushed cans and is gradually further reduced in cross-sectional area toward the outlet opening to provide a can crushing zone whereat the cans are gradually completely flattened by forces applied through the conveyor belt links which also carry the cans to and through the outlet opening. The conveyor belt members may be constructed and arranged to enable adjustment to achieve variable high density of crushed cans.
In the preferred embodiment, the magnetic separator means comprises a continuous non-magnetic belt member driven by an electric motor means about a magnetic pulley means. An upper horizontal portion of the belt member is located directly beneath the crusher means to directly receive crushed aluminum and steel cans by gravity fall from the crusher means and carry the crushed cans toward the magnetic pulley means. The lower portion of the belt member is upwardly inclined from the magnetic pulley means toward another pulley means and located directly above a crushed steel can discharge chute means. Crushed aluminum cans are discharged outwardly and downwardly relative to the belt member by momentum and gravitational forces as it turns around the magnetic pulley means and fall into the weighing means. Crushed steel cans are held on the belt member by magnetic forces as it turns around the magnetic pulley means and begins moving upwardly along the inclined path of the lower belt portion. When the magnetic force is no longer effective to hold the crushed steel cans on the lower belt portion, the steel cans fall away from the belt by gravitational and momentum forces. In the preferred embodiment, an outwardly extending rib member is provided on the belt to force steel cans away from the magnetic pulley means after the steel can has been carried therearound.
In the preferred embodiment, the weighing means comprises a hopper means suspended directly below and in close proximity to the magnetic separator means by a conventional load cell means which outputs electrical signals representative of the weight of the hopper means and empty cans therein. A door means, provided at the bottom of the hopper means, is movable between open and closed positions by an electric stepping motor means and associated linkage means which are constructed and arranged to open the door means at a variable rate whereby flow of cans to the air blower-type crushed can conveying means may be regulated. The weighing means further comprises a microprocessor control system wherein the load cell output signals are utilized to determine the amount of compensation to be dispensed to the customer for crushed aluminum cans received in the hopper means and to determine when to empty the hopper means. The construction and arrangement of the control system is such as to initiate certain procedures for each cycle of operation to assure that the machine is operating properly and that the customer receives the correct amount of compensation. These procedures comprise: initially obtaining a tare weight value representative of the empty weight of the hopper means; periodically obtaining an average crushed cans plus hopper weight value while cans are being processed in the machine; determining changes in succeeding average crushed cans plus hopper weight values and calculating the weight difference between the tare weight value and the last average crushed cans plus hopper weight value after there has been no change in average crushed cans plus hopper weight values for a predetermined period of time and then terminating operation of the can processing equipment; calculating the monetary value of the crushed cans in the hopper by multiplying the weight difference by a preset value per pound; dispensing compensation in accordance with the monetary value; and actuating the door actuating mechanism to dump cans from the hopper before the next cycle. In addition, whenever the weight of cans in the hopper exceeds a predetermined maximum value indicating that the hopper capacity has been reached, the operation of the can processing equipment is temporarily interrupted to enable operation of the door actuating mechanism to open the door, dump the crushed cans, and reclose the door whereupon the tare weight value is recalculated and the can processing equipment is reactivated. Other features of the control system which enable automatic continuous operation of the machine are hereinafter described in detail.
After the crushed aluminum cans are weighed to determine the amount of compensation to be dispensed, they are dumped and drop by gravity into a crushed can conveyor blown air passage means located at the bottom of the housing means whereby the crushed cans are blown to a large storage bin by a second air blower. In one embodiment, the crushed steel cans are also blown to a steel can storage bin by the second blower which is selectively connectable thereto. In addition, the second air blower may be selectively connected to unloading means associated with the storage bin for blowing the crushed cans from the storage bins to a discharge opening which is selectively connectable to a collection truck or portable storage bin.
The construction and arrangement of the can processing equipment is such as to enable the use of an unusually compact modular type housing means including a relatively small mechanical and electrical component section and a relatively large storage bin section. In the presently preferred embodiment, a single electric motor may be used to drive the belt conveyor means, the can crusher means, and the magnetic separator means with separate electric motors for each of the air blower means. Many of the parts and components may be made of high strength molded plastic parts to thereby reduce cost, maintenance and weight of the equipment, and improve air flow characteristics.